如何在合同中使用多个Counters.counter？

Question

pragma solidity >=0.7.0 <0.9.0;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract MyContract is ERC721, Ownable {
    using Strings for uint256;
    using Counters for Counters.Counter;

    Counters.Counter private totalSupply;
    Counters.Counter private commonSupply;
    Counters.Counter private rareSupply;
    ....

Answer 1

无论你喜欢什么:)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.3;

import "@openzeppelin/contracts/utils/Counters.sol";

contract EnumerableMap {
    using Counters for Counters.Counter;

    Counters.Counter public totalSupply;
    Counters.Counter public commonSupply;
    Counters.Counter public rareSupply;
    
    enum Counts {
        totalSupply,
        commonSupply,
        rareSupply
    }

    function increment(Counts _count) external {
        if(_count == Counts.totalSupply) {
            totalSupply.increment();
        } else if (_count == Counts.commonSupply) {
            commonSupply.increment();
        } else {
            rareSupply.increment();
        }
    }
}